Increasing focus has been paid to the seating needs of wheelchair users. Seating should be provided which can accommodate a variety of health issues and reasons for wheelchair use. In the past, adjustability has often been accomplished using custom seating which is designed to meet the needs of an individual user. However, custom seating is expensive and often inefficient with respect to the issue of inventory.
Moreover, even for standard seating which provides for some levels of adjustment, the user generally relies on a technician to set the position of the back support. While it is desirable to be able to remove a back support in order to store, or transport a wheelchair, it is highly preferable to provide for removal which retains the set adjustments. In addition, it is desirable to facilitate easy release and transport of the back support.
The current invention provides a back support for a wheelchair which can be adjusted independently with respect to a number of modes of adjustment; notably, adjustments can be made to seat depth, seat width, the back height above the seat, and the angle of incline with respect to a plane defined by the wheel chair canes to which the back support is mounted. A quick release mechanism is provided that permits single-handed release and removal while retaining the desired adjustment when the back support is remounted on the wheelchair. The back support assembly is frameless, and eliminates the additional weight that a support frame or carriage would add.
The back support assembly of the present invention comprises a back support encompassing two upholstered rigid back shells, one which is a lumbar support member, and one which is a thoracic support member. These two support members are joined either by a rigid connection or by a resilient hinge member. The back support is mounted by a series of L-shaped brackets which are linked to a mounting arm directly to mounting hardware on the canes of a wheelchair. The mounting arm is releasably suspended from two adjustable mounting posts of a cane bracket that forms a part of the mounting hardware which comprises a pair of cane mounting clamps. In particular, the lower of these mounting posts can be variably positioned in order to change the angle of incline of the back support. The mounting arms each have a pair of open C-shaped mounting recesses that are captured on the mounting posts by sliding the mounting arm backward along the post until the back support drops down into the top of the C to the mounted position. A spring biases locking pawl pivots to a closed position to lock the mounting arm on the upper mounting post. The pawl is triggered to an open position by a unitary mechanism that engages both of the two pawls at the same time. Preferably, the trigger mechanism can be a strap or cable that can extend upward to allow the user to hold the trigger and to engage a handle in the back support with the same hand. The four L-shaped brackets include longitudinal slots in the long arm for attachment to the rear of the back support members to provide for width adjustment so as to accommodate a variety of chair widths. The cane bracket has a dovetail connection to the cane clamp in order to be able to change the depth of the seat, by changing the location of the mounting posts of the cane bracket relative to the canes.